Not quite what Aziraphale meant, but he'll politely gloss over the fact.

"Oh, well, I don't see why there's any need for that. Unless you rather be called something else, of course." It's meant as nothing more than a blatantly polite and very (old) English sort of thing, but Aziraphale has found himself using it more often, lately. Something about being more at level with other people.

"I will say you look a tad bit different from what I've seen humans make you out to be, but then again they could hardly keep themselves to a specific look."